doc: fix formatting on PG recommendation

Previous commit (047287afbe0ddfaaafd05e9dbf25c1c7dea9a1be) broke
formatting on the formula, and also made mixed formula and text oddly,
which on second thought didn't look too good.

Add the note about the power of two to the following paragraph
instead, in prose.

Signed-off-by: Florian Haas <florian@hastexo.com>

diff --git a/doc/rados/operations/placement-groups.rst b/doc/rados/operations/placement-groups.rst
index 2f6fe141dbf90ccc079a367fc7f683100203de16..127fae9bf534fa35f1c2dbb5b9e494bb58b7d5f1 100644 (file)
--- a/doc/rados/operations/placement-groups.rst
+++ b/doc/rados/operations/placement-groups.rst
@@ -44,14 +44,15 @@ to balance out memory and CPU requirements and per-OSD load. For a single pool
 of objects, you can use the following formula::
 
                (OSDs * 100)
-   Total PGs = ------------ *(rounded up to the nearest power of 2)*
+   Total PGs = ------------
                  Replicas
 
-The rounding to the nearest power of two is optional, but recommended
-if you want to ensure that all placement groups are roughly the same size.
+The result should be **rounded up to the nearest power of two.**
+Rounding up is optional, but recommended if you want to ensure that
+all placement groups are roughly the same size.
 
 As an example, for a cluster with 200 OSDs and a pool size of 3
-replicas, you would estimate your number of PGs as follows:
+replicas, you would estimate your number of PGs as follows::
 
    (200 * 100)
    ----------- = 6667. Nearest power of 2: 8192